1. Field of the Invention
This invention relates to the loading of piles and more particularly it concerns novel techniques and apparatus for load testing and driving of piles into the earth under a body of water. Such piles are used, for example, to support piers, docks, bulkheads etc. Load testing of a pile involves the maintenance of a heavy weight on the top of the pile for a predetermined length of time during which the pile is monitored for downward movement. The load testing serves to indicate whether the pile as driven will be capable of supporting the load for which it has been designed. If the pile is not capable of supporting the load, it may be driven further to increase its load carrying ability.
2. Description of the Prior Art
Load testing and driving of piles into the earth under a body of water has previously been awkward and time consuming. In general, these techniques were carried out by driving a plurality of support piles adjacent the pile to be loaded for driving or testing. A platform was then constructed on the support piles to extend over the pile to be loaded; and a jack was positioned between the top of the pile and the load platform. When the jack was operated it would impose an upward force on the platform and the support piles while pushing downwardly on the pile being loaded.
These prior art arrangements presented several problems. If the pile was being tested for load carrying capacity and it began to settle, the load platform would have to be dismantled before the pile could be driven into the earth. Then, in order to retest the pile at its new height, it was often necessary to drive each support pile further into the earth to bring the load platform down to the new level of the top of the test pile. Also, the prior art pile loading structures could not be moved easily from one pile to another.